Conventionally, the organic electroluminescence device is known. For example, JPH11-312580A discloses such a device in which an anode, an organic electroluminescence layer, and a cathode, are laminated in this sequence on a base substrate. In this patent document, it is proposed that a method for electrically restoring a leakage portion among elements in the device after a plurality of elements of the organic electroluminescence device is formed on the base substrate. The method may be referred to as a self-restoration method for leakage portions.
In this method, the elements are formed, after that, a leakage portion among the elements is broken or destroyed by supplying electric current to the elements, then the leakage portion is oxidized and insulated. Thereby, it is possible to perform a self-restoration at the leakage portion in an electrical manner, and to turn the leakage portion into a nonconductive portion.
After the method, a protective layer is formed on the elements in order to protect the elements by a vapor deposition method. Thereby, an upper layer, e.g., cathode, and the nonconductive portion are covered with the protective layer. JP2009-211994A discloses a method for picking defective devices up by detecting an instantaneous leak current which shows a breakage when a thickness of the cathode is equal to or more than 135 nm (nanometers). This conventional method merely picks defective devices up, since an open defective portion created by the breakage portion may cause a short circuit when it is activated and driven at an actual usage.